ford 300ci piston search and build 500hp?
#61
Hi,
I have built a 300 6 (own 2 currently, 1 built 1 stock). The built one has basically the exact same stuff done to it as Colonel Flashman, except a slighty lower CR and its only bored 30 thou over. I doubt very much my engine has over 220 horsepower. I built it myself, so yes, I have seen the head apart many times, and those ports are nothing compared to a sbc (as much as I hate to bring a chebby v8 into this) I dont know as much as some on this board about how achieve lots of hp out of a smaller engine, but I have seen the lengths people like the FrenchtownFlyer over on fordsix have gone to achieve a 400 hp big six, and those engines are no where near streetable. My engine cost over 4.5 thousand to build, I cant imagine what one with nearly twice the Hp would cost. The SBC in my car has heads with 2 or 3 times the flow of the big six (dart heads), it has more cubic inches (383 stroker), more cam and no restrictions on type of fuel run (it runs on 115 octane leaded race gas, about 16$ a gallon) and exhaust (just open headers) and I regularly run it to 7 grand. It is, in no way shape or form, a streetable engine, and I doubt it even breaks 450 horse. And if I get written off as a "v8 zombie" for this post, well the first engine that I was going to build was a 351W,which I declined doing, and went out of my way to pick up a 6, so call me a zombie if you want.
I wouldn't always trust dyno's, a creative dyno operator can make it show pretty much anything he wants. I also wouldnt get to impressed by large build specs either, I could make anything I do look more impressive by listing every little part I used.
More on topic, I used speed pro hypereutics, which seemed of excellent quality, especially for the money. Fordsix is definetly the place to ask questions, there are a few guys there with high hp six cylinders (small and big sixes). I honestly think the best way to get 500 horse is to boost it. Way more reliable and it wont have that peaky power of a higher hp N/A engine.
Sorry for the rant, it was a long day today haha. Whatever you end up doing post lots of pictures.
Have a nice night,
I have built a 300 6 (own 2 currently, 1 built 1 stock). The built one has basically the exact same stuff done to it as Colonel Flashman, except a slighty lower CR and its only bored 30 thou over. I doubt very much my engine has over 220 horsepower. I built it myself, so yes, I have seen the head apart many times, and those ports are nothing compared to a sbc (as much as I hate to bring a chebby v8 into this) I dont know as much as some on this board about how achieve lots of hp out of a smaller engine, but I have seen the lengths people like the FrenchtownFlyer over on fordsix have gone to achieve a 400 hp big six, and those engines are no where near streetable. My engine cost over 4.5 thousand to build, I cant imagine what one with nearly twice the Hp would cost. The SBC in my car has heads with 2 or 3 times the flow of the big six (dart heads), it has more cubic inches (383 stroker), more cam and no restrictions on type of fuel run (it runs on 115 octane leaded race gas, about 16$ a gallon) and exhaust (just open headers) and I regularly run it to 7 grand. It is, in no way shape or form, a streetable engine, and I doubt it even breaks 450 horse. And if I get written off as a "v8 zombie" for this post, well the first engine that I was going to build was a 351W,which I declined doing, and went out of my way to pick up a 6, so call me a zombie if you want.
I wouldn't always trust dyno's, a creative dyno operator can make it show pretty much anything he wants. I also wouldnt get to impressed by large build specs either, I could make anything I do look more impressive by listing every little part I used.
More on topic, I used speed pro hypereutics, which seemed of excellent quality, especially for the money. Fordsix is definetly the place to ask questions, there are a few guys there with high hp six cylinders (small and big sixes). I honestly think the best way to get 500 horse is to boost it. Way more reliable and it wont have that peaky power of a higher hp N/A engine.
Sorry for the rant, it was a long day today haha. Whatever you end up doing post lots of pictures.
Have a nice night,
#63
#64
Exactly, OBC. If Ford made a 400 cuber I6, that would be different.
Let's not forget the 300 is already a 240 bored and stroked, and the fact an engine will produce numbers according to how it's built. That's why all these modern High-Po six's are putting out so much juice.
They were built for it.
The 300 was built for work.
Let's not forget the 300 is already a 240 bored and stroked, and the fact an engine will produce numbers according to how it's built. That's why all these modern High-Po six's are putting out so much juice.
They were built for it.
The 300 was built for work.
#65
Okay I read some of this thread and it was kinda a heated conversation, but I do have a question. I bought a 1986 f250 with 115000 miles. Its the worst 6 for compression (emissions stuff) anyways. I think its around 100-120 horse. Im in college and poor, so id like to play with it and get the horse power up with spending as little as possible. I know the pistons are probably dished pretty deep? But i have a 240 straight 6 from the 70s that came out of a combine and was going to put that head on the block with chevy rocker arms. So how much power/torque will I gain? I will probably use the 240 intake manifold to do away with the emissions pump. The compression ratio now should be 8. id like to get it closer to 9. Just for a little better fuel economy and some more power to play with. What do you guys think? (not looking for 500 horse, 150-170 would be super!)
#66
#70
Yes the 300 has dished pistons.
Swapping on a 240 head would bump up your compression by about .5 point. So if you have 8.0:1 now the 240 head would bump it up to 8.5:1.
Before swapping intakes check the carb opening in the intake. Some of the early engines had a smaller carb opening. The intake on your engine doesn't really have much emission stuff. The main thing is the egr carb spacer.
Dumping the stock exhaust manifold and swapping in a pair of EFI exhaust manifolds would also help. They are a dual outlet and flow much better then then your stock ex. manifold.
Swapping on a 240 head would bump up your compression by about .5 point. So if you have 8.0:1 now the 240 head would bump it up to 8.5:1.
Before swapping intakes check the carb opening in the intake. Some of the early engines had a smaller carb opening. The intake on your engine doesn't really have much emission stuff. The main thing is the egr carb spacer.
Dumping the stock exhaust manifold and swapping in a pair of EFI exhaust manifolds would also help. They are a dual outlet and flow much better then then your stock ex. manifold.
#72
My '86 Bronco really woke up with an Offy intake and EFI exhaust. Night and day. You'd get a lot more bang for your buck finding a used 4-bbl intake and carb plus a set of EFI exhaust manifolds than changing the head with the stock combo.
I've got a 240 head that needs to be finished out that will go on some day. The extra compression is just a plus. I ported it out pretty good. Even a little porting goes a long way for making power. Of course, head work is what makes an engine and good head work can run up the cost of an engine in a hurry.
Flat top pistons with a 240 head might be a little too tight depending on the deck height and compression height of the pistons. Outside of what's sold for 300s there are 351W pistons with the right compression height that will work. More options on dish size than the 300.
I've got a 240 head that needs to be finished out that will go on some day. The extra compression is just a plus. I ported it out pretty good. Even a little porting goes a long way for making power. Of course, head work is what makes an engine and good head work can run up the cost of an engine in a hurry.
Flat top pistons with a 240 head might be a little too tight depending on the deck height and compression height of the pistons. Outside of what's sold for 300s there are 351W pistons with the right compression height that will work. More options on dish size than the 300.
#73